Spatiotemporal evolution of urban expansion and spatial effect on sustainable development using multi-source night light data: A case study of the Greater Bay Area

Most of the world’s developed and competitive urban agglomerations are located in coastal regions. Numerous studies have found that cities in the Bay Area have an open economic structure, efficient resource allocation capacity and strong agglomeration spillover effects, the economic and ecological pressures arising from urban expansion have made regional sustainable development challenging. Therefore, this paper uses multi-source night light data from 11 cities in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) (2010-2023) to quantify the spatiotemporal evolution characteristics of urban expansion. It is found that the speed of urban expansion in the GBA is higher than the national average the intensity of this expansion remains relatively low. This is accompanied by suboptimal land utilization rates, diminished agglomeration effects, and increased spatial dispersion. Meanwhile, urban expansion has a significant positive strengthening effect on local sustainable development, but the indirect effect is negative, characterized by hysteresis and heterogeneity. The expansion of central cities no longer promotes regional sustainable development. Therefore, mitigating the siphoning effect of central cities, enhancing capital liquidity, and strengthening government policies on ecological and environmental regulation can help cities in the Greater Bay Area expand rationally and support regional sustainable development. • Using integrated nighttime light data, this paper analyze the spatiotemporal pattern of urban expansion in the Greater Bay Area from 2010 to 2023 • Urban expansion has a positive effect on regional sustainable development, but the central city is not affected by the expansion. • Urban expansion lacks significant spatial effects on the sustainable development of surrounding cities.